What's mock methylation?

Can anyone explain mock methylation. The best explanation that I've been able to coax out of the internet is (incubation with methylase in the absence of SAM (S-adenosyl methionine)). I don't know how this sort of methylation gets done, what gets added onto cytosine and how mock methylation differs from actual methylation. Help, please.

In what context did you encounter the term "mock methylation." There are many different types of methylation reactions in biology (e.g. proteins, for example the tails of histone proteins, can also be methylated). My guess would be that these mock methylation reactions are just negative control reactions.